FunctionDiscontinuities

FunctionDiscontinuities[f,x] finds the discontinuities of f(x) for x∈Reals. 

FunctionDiscontinuities[f,x,dom] finds the discontinuities of f(x) for x∈dom.

FunctionDiscontinuities[{f1,f2,…},{x1,x2,…},dom] finds the discontinuities of f1(x1,x2,…),f2(x1,x2,…),… for x1,x2,…∈dom.

Please visit the official Wolfram Language Reference for more details and examples on core symbols.